Hi all! New-ish owner of my rx8, got it in January and it is my first project car. In my last post I made I got a lot of great helpful feedback, so I wanted to make another post in hopes I could get my rx8 running at its very best again! I am having some small (and large) issues, so here I go-

Issue #1: Overheating in town (but very random) and hot start issues (but fine comp and new ignition system)

Probably the largest issue I have with the car. It has happened to me twice, but I am aware of how sensitive these cars are to heat, so it definitely worries me. I live a ways out of town, so when I drive my car around it tends to be a lot of higher speed driving. The first time I ever took it to work (about an hour away from home), the car made it great all the way to town on the highway, and through town. No issues. Lunch break comes, I drive about 5 minutes to a nearby gas station, turn the car off, go to start it again and it barely starts (cranked forever). This tends to be common with my car when it gets hot (hard starts). **I am in the 90’s psi on all faces of both rotors**. ESPECIALLY on warm days. It was 80 degrees when I began to have issues. When I went to drive the car home that day, it overheated halfway out of town at a light, shut itself off and wouldn’t start again until I pushed it to the side of the road and let it cool off. Immediately took it home and burped the coolant system (I’m an idiot and realized I hadn’t done this after flushing and re filling my coolant). Then took it on an hour drive through the small town I live in. Ripped it around pretty good, trying to get it to overheat. I never was able to. It was rainy and 70 degrees out when I did this. Figured however that my issue was fixed.

I have only taken it to work a handful of times since then. Today I took it again. As usual, did great on the way there in the morning. As the ambient temp rose on the afternoon, on my lunch break it yet again struggled to start. When I got off work I decided to take it to the car wash. Halfway there it overheated again (I take overheating as the gauge is 3/4 of the way up. There is also so much heat rising off my hood that it distorts my vision out the windshield). Let the car cool down, it started right up first crank after about half an hour. Took it home asap. On my way home there is a small town I have to pass through. Got stuck behind a car going 25 through there. I saw my gauge go up to the halfway mark. Immediately I looked for a place to pull over. Not even 10 seconds later I watched my gauge climb all the way the 3/4 again. Parked the car, waited twenty minutes, started it up (hard start) and got it home asap. Some things to note;
-My compression is generally alright
-E-fans kick on and run great
-No under tray
-Upgraded aluminum radiator
-No leaks from the weep hole of my water pump
-I have not looked into the thermostat yet
-There IS a very minor leak coming from the little plug at the bottom of my radiator
-Just the other day I drove this thing hard on a 1 1/2 hour round trip up and down a local mountain we have. It never overheated. (Ambient air temp was low at that elevation)

Issue #2: Riching out

This has been an issue since we got this car running. I’ve always thought it smelled really rich. (It has a cat delete but the smell of fuel is VERY strong). It also has an issue with flooding out if it stalls (Back when I first was learning to drive it this was a big problem but I don’t stall it anymore haha!). And it’s always popped out the exhaust if you let your foot off the gas. However the issue has been getting even worse lately…? Today when just cruising at 35mph it would pop out the back. But it’s more like a really strong sputter? If I rev it standing still it’ll really pop out the back hard which is new. Not sure what the deal is as I’ve replaced plugs, coils and wires and it almost seems to be worse after the new wires. (May be worth noting that when I took the new plugs out the other day they were very white. But this was a few days after it overheated so I figured it wasn’t running lean but rather got so hot it turned my plugs white).
The car also sounds ALMOST like it has a street port at idle and has sounded that way since we got it running. I assume it has something to do with how rich it’s running. However, another thing worth noting is that this is a used motor, and I have no idea what the history of the motor is, or whether or not it’s been rebuilt/messed with. The ECU is the ECU that came with my car. It has a junkyard number on it but it is clearly flashed to match my car’s vin, so who knows if it’s been tuned or not. I also do have a new MAF installed.

Issue #3: Shorting out?

Recently cleaned my ABS plug (ABS didn’t work at all) and now every time I plug the ABS plug in, A.) the pump will not turn off, even with the key fully out it’ll just run eternally. And B.) when it is plugged in, it causes my entire car to freak out, I lose all my gauges and power steering. As soon as you unplug the ABS plug, all said issues go away


Overall this thing gives me a constant headache, something new always pops up. It’s a really fun car when it does work. I just wish I could get it running 100% again. I will attach a video of how it sounds at idle. It is not an erratic idle, it just has a weird brap noise, but it’s quieter and not super noticeable. I live in Washington where in the summer we reach 100 degrees almost every day so hopefully I can get this overheating issue resolved